/Engine/Source/Runtime/Core/Public/Misc/FrameRate.h
Compute a desirable grid spacing for the specified screen units
True if a valid grid spacing was computed, false otherwise.
bool ComputeGridSpacing ( const float PixelsPerSecond, double & OutMajorInterval, int32 & OutMinorDivisions, float MinTickPx, float DesiredMajorTickPx ) const